Early Release Assistance Indication

[con2021]

Hello,

how to activate the Early Release Assistance Indication, to bypass the RRC_CONNECTED state.

This page from Telekom suggests that the user can do that to save much of the current consumption every cycle (about 50 mA for 20-30 seconds):

docs.iotcreators.com/.../nb-iot-network-information

[Stian Røed Hafskjold]

Hi, please have a look at the AT command AT%RAI: https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/nw_service/rai.html?cp=2_1_7_15

[con2021]

Thank you. It is not very clear what is the difference between the AT commands %RAI and %XRAI. Can you please clarify that

[Stian Røed Hafskjold]

Old %XRAI command is only for Control Plane (data) RAI and control plane data is only supported in NB-IoT (whole industry, not just nRF91).

In mfw1.3.0 %RAI will enable support for both CP RAI and AS RAI and then the application will need to give release assistance information via socket interface to modem.

[con2021]

Thanks, we use TCP, so to give the release order, we need first to know that we have received the ack. How can we know that the modem has received the TCP ACK (so that we can now release the RRC_CONNECTED mode)? Or is it done automatically that we activate the RAI command, and the network will release us directly after (within) the ack frame?

[Stian Røed Hafskjold]

ACK is handled by using the "one response" setting, which will keep the link open until the next downlink transmission (i.e. the TCP ACK) is done. When the feature is enabled, there are socket options to set the mode. The socket option should be set before the packet that will be ACKed is sent.

Unfortunately we do not have any examples showing this with TCP yet, but we have code for ICMP that utilizes the RAI functionality here:

https://github.com/nrfconnect/sdk-nrf/blob/332d2d1bc4aa335673aa0738e411aff0f2195915/samples/nrf9160/modem_shell/src/ping/icmp_ping.c#L343